This invention relates generally to indoor lighting fixtures employing high-intensity discharge lamps, which lighting fixtures are adapted to be mounted on a ceiling for producing semi-indirect or indirect lighting and more particularly to a reflector assembly therefor.
Since the introduction of high-intensity discharge lamps, greater use of such lamps has been made indoors. The last-mentioned lamps have found favor in school rooms, office and the like environs, since with the relatively high lumens per watt output of the lamps, fewer fixtures need be employed to achieve desired illumination.
Becasue the brightness of high-intensity discharge lamps is so great, however, these lamps are not well suited for use in conventional, direct illumination type indoor lighting fixtures. Instead, such lamps have been employed for indoor use in indirect or semi-indirect lighting fixtures. Examples of lighting fixtures of the last-mentioned type are illustrated in U.S. Pat. Nos. 3,950,638; 4,186,433; and 4,280,170. Each of the aforementioned patents illustrates a lighting fixture employing a high-intensity discharge lamp which is mounted in a socket arrangement suspended from the ceiling of a room. The vertically downwardly extending lamp is surrounded at its free end by a reflector arrangement which reflects light emitted from the lamp onto the ceiling surrounding the fixture which, in turn, illuminates an area of the room. The aforementioned patents illustrate a variety of reflector arrangements to accomplish the latter.
The provision of indirect or semi-indirect lighting fixtures for use indoors is itself not new. The prior art also reveals indirect lighting fixtures employed prior to the advent of high-intensity discharge lamps. Examples of those lighting fixtures are illustrated in U.S. Pat. Nos. 990,400; 1,966,583; and 2,136,862.
While the reflector arrangements of the last-mentioned patents are designed to reflect light from an incandescent lamp upwardly for illuminating an area of a room indirectly, such reflector arrangements have obviously not been designed for and appear that they would not, in most cases, be suitable for nor optimize the light output of a high-intensity discharge lamp.